Heavy Machinery / Agriculture
Excellent shock resistance and survivability make the VN-100 well suited for heavy machinery performance monitoring applications and can serve as an alternative to encoders that require a direct linkage to the moving members. VectorNav has a number of customers using the VN-100 for this application where the VN-100s have been operating in-field, under daily loads for several years without failures.
Customers with indoor applications or cave-mapping applications often seek to use the VN-100 as a dead-reckoning device. By integrating the accelerometers to derive displacement, positioning information can be obtained with the VN-100, however, without the assistance of GPS or other positioning system, position estimates obtained by integrating linear accelerations experience unbounded error growth. Even after calibration, residual biases and axis misalignments in the accelerometer measurements will quickly grow position estimate errors. For example, industrial-grade accelerometers, such as those built-into the VN-100, can yield errors on the order of 50 meters in just 60 seconds. If measurements from an indoor positioning system are available, VectorNav can provide custom filters for an indoor INS system.
Deep Bore Drilling / Pipeline Mapping
Customers often inquire about the suitability of the VN-100 for deep bore drilling or pipeline mapping applications. The aim is usually to track heading, orientation or position to help operators maintain a drilling direction or to map out a previously laid pipeline or borehole. It can be difficult to discern the Earth’s background magnetic field from disturbances in the surrounding environment, where there are long sections of pipeline encased in steel for example, which results in unreliable heading estimates. Gyroscopes of significantly better accuracies (and expense) as well as high operational temperature instruments used in the oil and gas field are usually required to maintain required performance (generally referred to as Measurement While Drilling). Mapping of existing holes of significantly shorter length might be possible with the VN-100 gyroscopes; however, VectorNav does not have any direct experience to comment on accuracies or requirements for maximum operation time. It is possible for VectorNav to develop custom solutions that incorporate external measurements of length of wire/sections of pipeline to bound position estimate errors or incorporate higher accuracy gyros for gyro-compassed heading measurements.
Customers attempt to fuse measurements from a VN-100, VN-200 or VN-300 and other sources to determine motion of a foot or other body part to obtain distance traveled or indoor position. For example, a developer of such a system may use the pause in motion experienced when a person’s foot is planted to the floor to apply this information to improve positioning estimates. Other kinematic constraints can be applied to further support the position or displacement measurements; however such systems suffer from the same errors.